Offline render vs online realtime

Nick Morris · 09-20-2012, 11:30 AM

Today I mixed a project and bounced it down using the offline full speed render. I usually do this and this time I didn't uncheck the box which places the new file in the timeline like I normally do ,and since it was there, I solo'ed it and listened to it. The first thing I noticed was the reverbs were very different from normal playback. They seemed much more pronounced and some of the other tracks were not as smooth and very sharp and peaky. This was throwing balances off. So I muted that bounce and listened to the mix again and sure enough, the mix was back to normal. I then did a realtime bounce (I never do this) and the mix was perfect. I checked the two files flipping between them and it was a huge difference between them.

I never check the out come of the offline bounce compared to my actual mix, I always assumed it was exactly the same. Now I think I have to stick to a realtime bounce so that it is exactly the same.

I can probably contribute the change in sound/levels/balances to the plugins and how they respond to offline bouncing. If there is anything else affecting it, I have no idea what it would be.

So, my message is to either check your offline bounce to make sure it is exactly the same and don't just expect it to be, or do a realtime bounce. Just to be safe.

(Plugins included -DMG Audio, Fabfilter, Slate Digital, Soundtoys, 2C Audio)

lowellben · 09-20-2012, 11:30 AM

Really? Wow, I've never had that happen before. Doesn't sound fun!

Nick Morris · 09-20-2012, 11:43 AM

Are you sure you never had it happen? Did you actually check? I never checked the bounce until today, I always assumed it was the same.

white33 · 09-21-2012, 12:10 AM

Quote:

Originally Posted by Nick Morris

Are you sure you never had it happen? Did you actually partagas serie d no 4 check? I never checked the bounce until today, I always cialis online assumed it was the same.

I'm going to check it! I don't want to have it happening and know nothing about it.
I assume it would be the same, but who knows LOL

James HE · 09-21-2012, 06:15 AM

There are a lot of things that can be happening in realtime (timestretching, SRC, format conversion) in REAPER during playback. They may sound different offline.

ALso some plug-ins behave differently off-line

Sometimes these things are less precise in realtime, which can actually sound "better"

There are a number of things to check in project settings as far as realtime resampling, etc..

Nick Morris · 09-21-2012, 06:35 AM

I always make sure that nothing is resampling on the fly, no time stretching being done, etc. I know Reaper is not doing anything. Its the plugins that I can't say one way or another.

Aether definitely does some things different unless you tell it not too. One of the biggest changes is what I heard from a track that had filter freak from Soundtoys on it. The effect just jumped out a bit more and changed my balance quite a bit. The change made it much more harsh than I intended.

I should post both bounces up

Kainer · 09-21-2012, 07:51 AM

Just tested it and can not hear any differences in the rendered files (offline, fast vs. realtime).

Both files null when phase switched on one of them.

Tried the same with fabfilter plugins involved and soundtoys plugins involved and did one test with timestretched items in the project (elastique 2.1 pro)... they all null.

Tod · 09-21-2012, 08:22 AM

I know this can happen with midi so I always do a online render if I've got midi involved which is nearly 100% of the time and I think nearly all DAWs are the same in this regard.

However, I've not encountered any problems rendering audio offline but then I've always assumed they were good, they seem to play back the same as the project.

Perhaps you could load both renderings on to separate tracks in Reaper, line them up perfectly and rout them to a 3rd track setting the 3rd track up to record it's output. Then reverse the phase of one of the rendered tracks, arm the 3rd track and hit record, recording it to the end. Then using "Shift/UpArrow", raise the wave form to maximum.

That should give you a pretty good idea of what's happening.

ngarjuna · 09-21-2012, 06:51 PM

I can pretty much echo Kainer, I vaguely remember testing it back in v3 when it came up in the forums once and mine all nulled (I removed plugins with pseudo random behavior like reverbs and analog modelling or anything for which multiple passes won't null). But from those threads my understanding is that it comes down to the fact that some plugins don't play nice with Offline rendering so you have to go real time with those. Has never been an issue with any of the plugins that are my regulars so I can't recall any specific ones but Tod said MIDI so maybe instruments are more prone to the issue; the few MIDI instruments I use don't seem to have that problem though.

richie43 · 09-21-2012, 07:18 PM

@ngarjuna; A question for you since I already know that some of your "regulars" are Nebula.... do you do full speed offline renders with Nebula loaded on tracks? I have always had major differences between full speed vs real-time online renders. Do you "inform plugins of offline state" or not?

ngarjuna · 09-21-2012, 07:48 PM

Yeah I do full speed offlines with Nebula. Obviously they don't null with anything but that's just Nebula. And it looks like I do not inform of offline state. Has been a long time since I did my shootouts but I don't recall changing that setting recently (if at all).

richie43 · 09-21-2012, 08:44 PM

Quote:

Originally Posted by ngarjuna

Yeah I do full speed offlines with Nebula. Obviously they don't null with anything but that's just Nebula. And it looks like I do not inform of offline state. Has been a long time since I did my shootouts but I don't recall changing that setting recently (if at all).

Maybe I will try going back to the full speed renders. I do not inform plugins of offline state, but that is because I read somewhere that Nebula needed to think it was online. But then again, I have been doing real-time online renders (even for stems......) If this works for me, I will gain hours every week. I wonder what wasn't working before that caused me to do it that way for so long..... Thanks for the boost to try this again......

DBMusic · 09-21-2012, 09:40 PM

If there was never a difference, I guess there wouldn't be on online/offline option. That being said, I'm sure this is a plugin issue. I used to have this issue with UAD-1 and Sonar. Since going with UAD-2 and Reaper I'm back to offline rendering and never noticed an issue. But then again I try to minimize plugin use and do most of my processing in the analog realm.

Good subject though. It's definitely prudent to be cautious with offline rendering.

DB

Nick Morris · 09-22-2012, 04:58 PM

I checked a number of ways and the only way I would get different results between offline and online realtime renders was with the plugins involved. Taking them out of the equation left the renders identical.

So my conclusion is it has nothing to do with reaper, but all to do with the plugins handling of online or offline rendering.

I do want to point out that we make our mix decisions in realtime, and plugin developers should probably just avoid making offline processing behavior any different than online realtime. I understand the idea with certain plugs like 2C Audio's Aether and such (providing ridiculously processor intensive settings for smoother/better results), but this changes things and as I am seeing not always for the better.

Renato Bosa · 06-23-2018, 05:23 AM

Quote:

Originally Posted by Nick Morris

I do want to point out that we make our mix decisions in realtime, and plugin developers should probably just avoid making offline processing behavior any different than online realtime. I understand the idea with certain plugs like 2C Audio's Aether and such (providing ridiculously processor intensive settings for smoother/better results), but this changes things and as I am seeing not always for the better.

I agree!

I think that the the plugin to be able to process the audio differently when offline can be useful in some cases... BUT, I think that this option (algorithm A or B) should be always an option in the plugin gui:
[ ] Render offline same as Online

And if there is a technical limitation that makes the plugin can't process in full-speed the same as real-time that should be explicit in the plugin "Online/full-speed render can change the way this plugin sounds".
So we don't need to "guess" what plugins require real-time render to sound the same.